Time-varying diffraction effects in the propagation of an electromagnetic pulse in vacuum
Belenov E. M., Nazarkin A. V.
A new optical effect is predicted: As an electromagnetic field pulse with a steep leading edge propagates in vacuum, the transverse distribution and strength of the field at the leading edge remain constant. This effect is linked with the existence of a time-dependent "vacuum dispersion." An analogy is drawn between this effect and Sommerfeld and Brillouin's problem of the propagation of a signal in a dispersive medium and also with the coherent propagation of a small-area pulse (a Οπ pulse) in a gas of resonantly absorbing two-level particles.
Home
![](/ps/1149/article_17388_800_head.png "A new optical effect is predicted: As an electromagnetic field pulse with a steep leading edge propagates in vacuum, the transverse distribution and strength of the field at the leading edge remain constant. This effect is linked with the existence of a time-dependent "vacuum dispersion." An analogy is drawn between this effect and Sommerfeld and Brillouin's problem of the propagation of a signal in a dispersive medium and also with the coherent propagation of a small-area pulse (a <i>Οπ </i>pulse) in a gas of resonantly absorbing two-level particles.")